Einfluss Mittlerer Ionenkonzentrationen auf die Elektrostatische Energie von Fadenmolekülionen in Lösung

Using polymethacrylic acid as example it is shown that the electric charges cause the chain molecules to become expanded. The expansion decreases when the concentration is increased or when salts are added. This contraction is ascribed to an increase of ionic strength. A general expression is developed for the electrical free energy of statistically coiled, electrically charged chain molecules. In this the end‐to‐end distancehof the polymer molecule is used as characteristic parameter for the shape. The distribution of ions with opposite charge and the variations of potential inside and outside of a coiled molecule are computed in accordance with the method ofDebijeandHückel. In special cases, i.e. various concentrations and different amounts of added salt, the electrical free energy is calculated as a function ofh(the distribution of the oppositely charged ions being taken into account). Using the free energy‐hfunction so found,h2and the specific viscosity are calculated and compared with experiments on polymethacrylic acid.